Water treatment equipment is broadly used in many industry fields. Traditional water treatment processes treat water by desalting source water. Typically, desalted equipment combines ion-exchange technology and electrodialysis technology. For example, Chinese Patent No. 96244875.4 shows an EDI device which combines ion-exchange technology and electrodialysis technology. In Chinese Patent No. 96244875.4, anion and cation resin is placed inside a dilute water chamber of the electrodialysis device and positive and negative electrodes are placed outside the device.
Chinese Patent No. 00220610.2 shows a multi-surface volume EDI module which consists of positive and negative electrodes, membrane bags and a frame. The anion and cation ion exchange membranes are combined with isolation net sheets to form membrane bags which fold to include concentrate water channels and dilute water channels. Each of the concentrate water channels and the dilute water channel connects to a different individual water collection chamber extending from a dilute/concentrate collection pipe. The dilute water channels are filled with ion-exchange resins, and consist of linked together rectangle channels.
Traditional EDI modules use net sheet as the material for resin water distributing and water collection. This material can cause the problems of resin seepage and loss. Moreover, the known materials can block the channels that are used for feed water. U.S. Pat. No. 6,190,528, issued Feb. 20, 2001 to Xiang Li et al. discloses a helical EDI apparatus having the resin seepage disadvantages described above. U.S. Pat. No. 6,190,528 is incorporated herein by reference in its entirety.